The present invention relates to a device for cleaning the face of an optical fiber tube employed in an image-forming apparatus, the optical fiber tube acting as a means for exposing a reproduction surface to optical images.
Optical fiber tubes are conventionally used as a means for exposing surfaces to optical images because such optical elements not only form distinct point images but limit diffusion of rays while retaining the desired image strength in a vacuum. When optical fiber tubes are used for projecting optical images onto a surface, such as a photoconductive drum surface in an electrophotographic copier, the face of the tube is brought to a position usually about 0.2 to about 0.5 mm from the surface. Accordingly, the tube face is prone to having toner, dust or the like rays deposited thereon, which particles block the emitted from the tube and thus adversely affect the image produced on the exposed surface.
To overcome this problem, the tube can be removed from the apparatus and its free cleaned, or an air stream can be applied to the periphery of the tube face to expel the toner, dust or the like, or the clearance between the tube face and the drum surface can be sealed. However, it is impossible to perfectly prevent the tube face from becoming stained by the application of air or by sealing, thus resulting in the need to remove the tube from the apparatus for cleaning with a cloth or the like (either at predetermined times or when adversely affected images are produced), and this is cumbersome and time consuming.
Although U.S. Pat. No. 4,074,217 discloses a cleaner which is adapted to wipe an end face of an assembly of focusing light-transmitting members every time the original receptacle of a copying machine is reciprocated, utilizing the reciprocation of the receptacle, such a cleaner system is not usable in an image-producing apparatus wherein the optical fiber tube therein must be positioned very close to the surface on which the image is to be produced.
An object of the present invention is to provide a device for cleaning the face of an optical fiber tube incorporated in image-forming apparatus. More particularly, the main object of the invention is to provide a device for cleaning the face of such an optical fiber tube automatically, easily and effectively, utilizing the usual operation of the image-forming apparatus to thereby overcome the foregoing problems heretofore encountered.